The dark-field, empty-field and instrument accommodations were measured for a number of emmetropic and ametropic subjects to investigate (1) the natural individual variation in these accommodation levels, (2) correlations and regressions between some of the variables, (3) the effect of refractive error on the anomalous accommodation levels and (4) response times to dark- and empty-field conditions. The results show that (a) some subjects have highly stable dark and empty-field accommodation levels, but others exhibit significant fluctuations, (b) dark- and empty-field accommodation levels have a high correlation and regression, but dark-field and instrument accommodations correlate less well, and (c) some subjects respond quickly to the dark- and empty-field conditions, whereas others have response times of several minutes.